In general, a washing machine is classified into a pulsator type, a drum type and an agitator type washing machine.
Referring to FIGS. 1 and 2, a drum type washing machine will be described as an embodiment of a conventional washing machine.
The drum type washing machine includes a body 10, an outer tub 20 mounted within the body 10, a drum 30 rotatably mounted within the outer tub 20, a driving unit for driving the drum 30. An opening 11 is formed in front of the body 10 for loading/unloading the laundry, and a door 40 is coupled to the opening 11 for opening/closing the opening 11.
A damper 21 is provided between the outer tub 20 and the body 10. A heater 60 is provided within the outer tub 20, such that it is possible to control a wash water temperature. The drum 30 is rotatably mounted within the outer tub 20 and a plurality of through holes 31 is formed on a circumferential surface of the drum for drawing/discharging wash water.
The driving unit includes a motor 71 to drive the drum 30, a belt 72 connected with the motor to transmit the driving force of motor 71 to the drum 30. Alternatively, the driving unit may employ a motor directly connected to the drum 30.
In the conventional drum type washing machine, commonly, the laundry and detergent is mixedly supplied within the drum 30. Hence, washing cycles including a wash, a rinse and a spin step according to a control signal of a controller (not shown) are automatically performed. Each of the wash, the rinse and the spin step could be operated individually.
Recently, a washing machine using steam has been under development for improving washing performance as well as economizing in wash water and energy. Commonly, the washing machine using steam has been supplied new components such as a steam generator.